'The Ukrainian and Russian sides agreed, that new sorts of contracts are necessary', he said.

According to Šefčovič, the documents will have to meet the standards of the European law.

Russia's energy minister Aleksandr Novak added that the sides discussed changes in the EU legal frameworks. 'This law is being implemented in the Ukrainian legal system. This also makes an impact on further relations starting from 2020,' he stressed.

On July 17, Šefčovič met with the Ukrainian and Russian delegation to talks through the issues of the transit of the Russian gas via the territory of Ukraine. The parties mentioned a peace agreement between Ukraine's and Russia's major gas operators as the way to solve the issue, but no actual decision was made.

Earlier, Petro Poroshenko, the President of Ukraine, said the countries of the European Union and the U.S. support the position of Ukraine against the construction of the Nord Stream 2 gas pipeline and preservation of the role of Ukraine in the gas transit.

He reminded that the Stockholm Arbitration Court satisfied the demands of the 'Naftogaz' in the lawsuit to 'Gazprom' and got a $4,63 billion compensation for the transit gas that had been agreed on but not delivered by Gazprom.

'It is possible to defend against Russia only by the united and effective actions of the world. According to my deep conviction, there is no alternative,' Poroshenko added.